Characterization of the fruit proteolytic system of Bromelia serra Griseb. (Bromeliaceae) and its application in bioactive peptides release.

A crude extract with proteolytic activity was prepared from edible fruits of Bromelia serra, containing cysteine peptidases with molecular masses between 24.1 and 25.9 kDa.

Bromide counterion as a spectroscopic sensor at the interface of cetyltrimethylammonium micelles.

The strong UV absorption of the bromide in aqueous solution undergoes a remarkable red shift of more than 10 nm induced by the addition of the salts that constitute a saline buffer. The maximum absorption wavelength of the bromide is displaced from approximately 194 nm in ultrapure water to wavelengths above 200 nm, depending on the composition of the solution. The bromide spectrum as counterion of the cetyltrimethylammonium in the surfactant CTAB also shows sensitivity to the aggregation behavior of the tensioactive, being able to detect intermolecular interactions even at concentrations lower than the critical micelle concentration.

Host-guest molecular interactions in vanillin/amylose inclusion complexes.

The interaction of 4-hydroxy-3-methoxybenzaldehyde (vanillin) and Hylon VII due to the formation of an inclusion complex is studied using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and circular dichroism (CD). The results confirm the close interaction among the different functional groups of vanillin and its host. In addition, a second case study was carried out with an amylose from a different source (100% amylose [APT III]).

Customized design of electronic noses placed on top of air-lift bioreactors for in situ monitoring the off-gas patterns.

A specially designed electronic nose was coupled to an air-lift bioreactor in order to perform on-line monitoring of released vapors. The sensor array was placed at the top of the bioreactor sensing the headspace in equilibrium with the evolving liquor at any time without the need of aspiration and pumping of gases into a separated sensor chamber. The device was applied to follow the off-gas of a bioreactor with Acidithiobacillus thiooxidans grown on beds of elemental sulfur under aerobic conditions.

Violet ZnSe/ZnS as an alternative to green CdSe/ZnS in nanocrystal-fluorescent protein FRET systems.

Fluorescent proteins from the green fluorescent protein family strongly interact with CdSe/ZnS and ZnSe/ZnS nanocrystals at neutral pH. Green emitting CdSe/ZnS nanocrystals and red emitting fluorescent protein dTomato constitute a 72% efficiency FRET system with the largest alteration of the overall photoluminescence profile, following complex formation, observed so far. The substitution of ZnSe/ZnS for CdSe/ZnS nanocrystals as energy donors enabled the use of a green fluorescent protein, GFP5, as energy acceptor.

Silicon based materials for drug delivery devices and implants.

This patent review focuses on silicon based materials for drug delivery systems and implant devices devoted to medical applications. The article describes some representative examples of the most depictive silicon based compounds associated with drug release formulations and tissue engineering biomaterials. Ranging from inorganic to organic and hybrid inorganic-organic silicon compounds, the paper referrers to patents describing inventions which make use of the best properties of silicon dioxide, silica aerogel and xerogel, silicon bioactive materials, silicones and ormosils, pointing out the usefulness of each kind of compound within the invention embodiment.

Electronic nose screening of limonene release from multicomponent essential oils encapsulated in pectin gels.

Multicomponent essential oils Tagetes Minuta and Poleo as well as pure limonene were encapsulated in Tween doped-high methoxylated pectin gels. Optical microscopy reveals that the obtained gels containing limonene consisted in a highly heterogeneous oil-in-water emulsion stabilised by the gelled medium. The influence of limonene encapsulation in pectin gelation kinetics and the gel structural properties were followed by dynamic rheological measurements.

Dynamic rheological measurements and drug release kinetics in swollen scleroglucan matrices.

The structure of scleroglucan gel matrices was characterized by dynamic rheological studies. The results were compared with the release kinetics of theophylline in analogous samples using a Franz diffusion cell, fitting the drug release data with a semi-empirical power law. Dynamic rheology gave information about the viscous and elastic components (loss and storage moduli, respectively) of the gel which could influence the drug-release profiles.

Correlation between gel structural properties and drug release pattern in scleroglucan matrices.

The drug delivery behavior of scleroglucan hydrogels was correlated with the structural features found by means of steady-state fluorescence studies. Theophylline at 0.4% in weight was used as the model drug and its release was measured using a Franz cell device.